This invention relates to network security and particularly to defending against virus and worm attacks.
A worm is a program that self-propagates across a network, exploiting security or policy flaws in services. Often a worm scans a network for potential targets. A denial of service may occur when network bandwidth is consumed as a result of an excessive number of connections that are opening during worm probing of a network.
A virus is an intrusive program that infects computer files by inserting copies of itself in those files. The copies may be executed when the file is loaded into memory, allowing the copies to infect still other files.
The security of an enterprise, such as a network, is dependent to some degree on the enforcement of security provisions at each station on that network. Generally, security systems may be software-based in the form of applications or operating system kernel drivers on individual stations. These capabilities are vulnerable to malicious/mal-configured/faulty components that can actively intrude or step on the operating system functions locally or remotely. Also, software-based critical security applications can be turned off by the user, thereby reducing the overall security and manageability of an enterprise network.
Fast propagating worms are a severe threat to networks today. The propagation rate of these worms is high enough to infect the entire Internet within minutes. This implies that a network administrator has no time to react to such worms. Moreover, these fast propagating worms may also consume significant portions of network bandwidth thereby making it difficult for a network administrator to access the infected systems or networks.
Thus, there is a need for a way to protect systems, for example, when operating system resident security agents have been tampered with.